Can radio frequency identification record when workers arrive and leave? And what challenges does this pose?
Yes. A number of companies are utilizing various forms of RFID technology to record when employees arrive and leave. Often, however, this is more about monitoring safety than ensuring that workers do not arrive late or leave early.
Employees can be required to present a passive high-frequency (HF) badge to an RFID reader, in order to record their arrival and departure times. Some firms want to automate attendance-taking, to avoid problems if a staff member forgets to present his or her badge.
The challenge is that the human body is mostly composed of water, which absorbs ultrahigh-frequency (UHF) radio waves. So if a tag was close to a person's body, or if that individual was located between the tag and the reader, it might not be possible to interrogate the tag. Convergence Systems Ltd. (CSL) has developed a battery-assisted tag that greatly improves read rates (see Pilots of CSL's Battery-Assisted Passive UHF RFID Card Underway).
Some firms have also affixed tags to workers' gear. For example, at construction sites, employees are required to wear a hard hat. By affixing a tag to that hat, a company can make sure that the tag can be kept away from the wearer's body, in order to ensure accurate read rates. Every time a tag is read, the reader provides its serial number and a time stamp, so the employee is associated with that particular serial number, and the time that he or she enters or leaves the premises is easily recorded (see At Construction Sites, RFID Tracks Arrivals, Departures and SmartHat Developers Hope to Make Construction Sites Safer).
—Mark Roberti, Founder and Editor, RFID Journal